| 1 | /* This file is part of the KDE libraries |
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| 2 | SPDX-FileCopyrightText: 2001, 2002, 2007 David Faure <faure@kde.org> |
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| 3 | |
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| 4 | SPDX-License-Identifier: LGPL-2.0-or-later |
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| 5 | */ |
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| 6 | |
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| 7 | #ifndef klimitediodevice_p_h |
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| 8 | #define klimitediodevice_p_h |
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| 9 | |
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| 10 | #include <QDebug> |
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| 11 | #include <QIODevice> |
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| 12 | /** |
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| 13 | * A readonly device that reads from an underlying device |
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| 14 | * from a given point to another (e.g. to give access to a single |
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| 15 | * file inside an archive). |
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| 16 | * @author David Faure <faure@kde.org> |
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| 17 | * @internal - used by KArchive |
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| 18 | */ |
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| 19 | class KLimitedIODevice : public QIODevice |
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| 20 | { |
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| 21 | Q_OBJECT |
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| 22 | public: |
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| 23 | /** |
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| 24 | * Creates a new KLimitedIODevice. |
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| 25 | * @param dev the underlying device, opened or not |
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| 26 | * This device itself auto-opens (in readonly mode), no need to open it. |
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| 27 | * @param start where to start reading (position in bytes) |
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| 28 | * @param length the length of the data to read (in bytes) |
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| 29 | */ |
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| 30 | KLimitedIODevice(QIODevice *dev, qint64 start, qint64 length); |
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| 31 | ~KLimitedIODevice() override |
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| 32 | { |
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| 33 | } |
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| 34 | |
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| 35 | bool isSequential() const override; |
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| 36 | |
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| 37 | bool open(QIODevice::OpenMode m) override; |
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| 38 | void close() override; |
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| 39 | |
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| 40 | qint64 size() const override; |
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| 41 | |
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| 42 | qint64 readData(char *data, qint64 maxlen) override; |
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| 43 | qint64 writeData(const char *, qint64) override |
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| 44 | { |
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| 45 | return -1; // unsupported |
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| 46 | } |
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| 47 | |
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| 48 | // virtual qint64 pos() const { return m_dev->pos() - m_start; } |
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| 49 | bool seek(qint64 pos) override; |
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| 50 | qint64 bytesAvailable() const override; |
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| 51 | |
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| 52 | private: |
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| 53 | QIODevice *m_dev; |
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| 54 | qint64 m_start; |
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| 55 | qint64 m_length; |
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| 56 | }; |
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| 57 | |
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| 58 | #endif |
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| 59 | |
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